df89a86463
A list_del() debugging check. Has been in -mm for years. Dave moved list_del() out-of-line in the debug case, so this is now suitable for mainline. Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
80 lines
2.0 KiB
C
80 lines
2.0 KiB
C
/*
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* Copyright 2006, Red Hat, Inc., Dave Jones
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* Released under the General Public License (GPL).
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*
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* This file contains the linked list implementations for
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* DEBUG_LIST.
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*/
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#include <linux/module.h>
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#include <linux/list.h>
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/*
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* Insert a new entry between two known consecutive entries.
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*
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* This is only for internal list manipulation where we know
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* the prev/next entries already!
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*/
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void __list_add(struct list_head *new,
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struct list_head *prev,
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struct list_head *next)
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{
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if (unlikely(next->prev != prev)) {
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printk(KERN_ERR "list_add corruption. next->prev should be %p, but was %p\n",
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prev, next->prev);
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BUG();
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}
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if (unlikely(prev->next != next)) {
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printk(KERN_ERR "list_add corruption. prev->next should be %p, but was %p\n",
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next, prev->next);
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BUG();
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}
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next->prev = new;
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new->next = next;
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new->prev = prev;
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prev->next = new;
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}
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EXPORT_SYMBOL(__list_add);
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/**
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* list_add - add a new entry
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* @new: new entry to be added
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* @head: list head to add it after
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*
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* Insert a new entry after the specified head.
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* This is good for implementing stacks.
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*/
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void list_add(struct list_head *new, struct list_head *head)
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{
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__list_add(new, head, head->next);
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}
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EXPORT_SYMBOL(list_add);
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/**
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* list_del - deletes entry from list.
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* @entry: the element to delete from the list.
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* Note: list_empty on entry does not return true after this, the entry is
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* in an undefined state.
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*/
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void list_del(struct list_head *entry)
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{
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BUG_ON(entry->prev->next != entry);
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BUG_ON(entry->next->prev != entry);
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if (unlikely(entry->prev->next != entry)) {
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printk(KERN_ERR "list_del corruption. prev->next should be %p, "
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"but was %p\n", entry, entry->prev->next);
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BUG();
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}
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if (unlikely(entry->next->prev != entry)) {
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printk(KERN_ERR "list_del corruption. next->prev should be %p, "
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"but was %p\n", entry, entry->next->prev);
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BUG();
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}
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__list_del(entry->prev, entry->next);
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entry->next = LIST_POISON1;
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entry->prev = LIST_POISON2;
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}
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EXPORT_SYMBOL(list_del);
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